DENVER — The quality of tornado warnings has improved dramatically since the early days of radar, a veteran weather official says, but success rates have leveled off in recent years.

It will take a series of steps — some relatively simple and others expensive and years from reality — to see a significant improvement in accurately detecting tornadoes and providing additional lead time for people in the path of tornadoes, said Don Burgess, research scientist at the Cooperative Institute for Mesoscale Meteorological Studies and adjunct professor of meteorology, both at the University of Oklahoma.

“We find ourselves on somewhat of a plateau” in “skill scores,” Burgess said at the national storm chasers’ convention in Denver. “We have improved over where we used to be. … Where do we go from here?”

Fearful of inciting public panic, the national weather bureau forbade the issue of tornado warnings until the 1950s. Even when the warnings began being issued, Burgess said, they “were not very skillful.”

As recently as the 1970s, tornadoes touched down only 20 percent of the time warnings were issued. Of the tornadoes that touched down, warnings were issued on less than 10 percent of them.

“We missed a lot of tornadoes and we issued a lot of poor warnings,” Burgess said while later discussing the data in more detail.

The arrival of Doppler radar technology gave researchers and meteorologists more tools to understand how the storms worked. During a project to evaluate the effectiveness of Doppler radar, lead times for tornadoes jumped several minutes and the false alarm rate dropped by more than 20 percent.

That led to the deployment of Doppler radar nationwide, Burgess said, though that wasn’t completed until the late 1990s. Detection rates, lead times and false-alarm rates all improved as the radars came into use.

“But we need to do better overall,” he said. “So how do we improve?”

One way, he said, is to determine and duplicate best practices. Some weather service bureaus are consistently better at detecting threats and issuing warnings, he said, so the National Oceanic and Atmospheric Administration’s warning decision training branch is working to collect how they do what they do and making that information available throughout the branch network.

Another step is improving reports from storm spotters — whether they are from storm chasers, the public or the network of strategically positioned spotters.

“I know we get many good reports … but we still deal with a significant noise level” — meaning reports that are poor or wildly contradictive to other reports from the same area, Burgess said.

“We have spotters and we have radar and we need to work together,” he said.

New smartphone apps are being rolled out that allow residents to report weather events such as hail or snow where they are, giving meteorologists “ground truth” for storms indicated on radar — and apps are being developed to send NOAA warnings to smartphones.

Researchers hope to develop and deploy smaller, lesser-cost radars on towers that can provide data on what’s happening in the “boundary layer” — that space between the cloud base and the ground, Burgess said.

Vortex2, a two-year field study of tornadoes in the nation’s midsection, revealed that factors near the surface of the Earth play a much greater role in the development of tornadoes than previously realized, he said, and a network of radars scattered throughout Tornado Alley would help give meteorologists a clearer picture of the evolving conditions during potentially severe weather.

Attempts to have the radars placed on cellphone towers have met with resistance so far, he said, so researchers are looking for other ways to set up the radars.

“The private sector has to get involved,” Burgess said.

If a network of these boundary layer radars is to be established, “it’s going to have to be with a lot of private-sector funding,” he said.

The next big leap in radar technology — phased array radar — has already been identified, Burgess said. It will allow meteorologists to scan the atmosphere much more rapidly than currently — and to aim multiple radar beams at the same storm during severe weather.

“It’s another world” in radar capabilities, he said. “Phased array will be a godsend to the warning community.”

But much work needs to be done in developing the delivery platforms for the new radars and building computers that can rapidly process the high volume of data they provide, he said. As a result, he doesn’t expect the phased arrays to arrive for more than a decade.

In the meantime, upgrades to the dual-polarization radars now being deployed nationwide should serve as an effective interim measure.

By 2020, weather researchers hope to be able to accurately predict tornado formation 80 percent of the time and have a lead time of 45 minutes, Burgess said. The false alarm rates will always be higher than people will like, he said, because forecasters err on the side of caution.

As you comment, please be respectful of other commenters and other viewpoints. Our goal with article comments is to provide a space for civil, informative and constructive conversations. We reserve the right to remove any comment we deem to be defamatory, rude, insulting to others, hateful, off-topic or reckless to the community. See our full terms of use here.

More in News

St. Paul Public Schools has established a where anyone can donate money to pay off anonymous students’ overdue lunch accounts. The district said it’s a response to a social media campaign that caused many people to call the district asking how they can give. Families in the district owe nearly $28,000 on school lunches. All district schools provide free breakfasts and most offer...

Weekend snow is on tap for much of southern Minnesota and western Wisconsin, with 3 to 6 inches expected in the Twin Cities and more elsewhere. The snow will be followed next week by the season’s first subzero temperatures. According to the National Weather Service, a slow-moving low pressure system will spread snow into western Minnesota on Saturday morning and...

Hennepin County Medical Center in downtown Minneapolis is planning to reduce its workforce by as much as 4 percent next year. The hospital plans to eliminate up to 275 full-time positions to balance the budget and keep the opening of a $220 million ambulatory and outpatient surgery center on schedule for 2018, the Minneapolis Star Tribune reported. The hospital’s workforce...

Two construction companies have agreed to pay a combined $147,500 in fines over safety violations in the death of one worker and injuries to another during construction of the Minnesota Vikings’ new stadium in downtown Minneapolis last year. Berwald Roofing is paying $113,200 for three violations, while Mortenson is paying $34,300 for one violation. The penalties are lower than Minnesota’s...

Larry Stanger, the Inver Grove Heights police chief who has been on paid leave since April while being investigated for alleged wrongdoing, will resign as part of a separation agreement reached between him and the city. The city council is scheduled to consider approving the agreement at its regularly scheduled meeting Monday. City Administrator Joe Lynch and City Attorney Tim...

St. Paul police are investigating a case of possible embezzlement at Town and Country Club. Police were notified of the matter on Monday and an investigator met with representatives of the club, said Steve Linders, a St. Paul police spokesman. A brief police report indicates the incident of possible embezzlement began in January 2010 and ended Dec. 2. Police are...